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new here, been following this. we have a new unit, replaced july 08. ac all summer good, after first few weeks of cold, dss. not always, not when emergency heat used, but 1- 2 times a day. am going to clean coils,pan,drain,filter... big question is ,what is this mold and is it harmfull? name with niger in it makes me think black mold?

Thank you for your input. It will be interesting to me when this is all figured out. Just way too many loose ends for me to feel confortable that I have seen/smelled the last of it...
On the quote above: I believe the reference was to niger asparillius (sp) or whatever. It does not appear to me that the poster was thinking what your thinking he/she was thinking. I think.

Thank you for your input. It will be interesting to me when this is all figured out. Just way too many loose ends for me to feel confortable that I have seen/smelled the last of it...
On the quote above: I believe the reference was to niger asparillius (sp) or whatever. It does not appear to me that the poster was thinking what your thinking he/she was thinking. I think.

new here, been following this. we have a new unit, replaced july 08. ac all summer good, after first few weeks of cold, dss. not always, not when emergency heat used, but 1- 2 times a day. am going to clean coils,pan,drain,filter... big question is ,what is this mold and is it harmfull? name with niger in it makes me think black mold?

Ok give you the benefit of the doubt.

The big answer to your big question can be answered by looking up Aspergillus Niger, yes , its black mold. So you probably have A. Niger lurking around in your home , how does that make you feel ?

Jattibb you need to get you mind out of the gutter an use google a bit more appropriately. Stachybotrys is the notorious black mold.
Stachybotrys
From Wikipedia, the free encyclopedia

Stachybotrys

Scientific classification
Kingdom: Fungi

Phylum: Ascomycota

Class: Sordariomycetes

Order: Hypocreales

Family: Dematiaceae

Genus: Stachybotrys

Species
S. chartarum
S. cylindrospora

Stachybotrys is a genus of molds, or asexually-reproducing, filamentous fungi. Closely related to the genus Memnoniella,[1][2] most Stachybotrys species inhabit materials rich in cellulose.

The most infamous species, S. chartarum (also known as S. atra) is known as "black mold" or "toxic black mold," and is frequently associated with poor indoor air quality that arises after fungal growth on water-damaged building materials.[3] It is known to produce trichothecene mycotoxins including satratoxins.

nice to know you cany say the word niger, about anything, w/o someone playing the race card. that is NOT what i meant! simple question requiring a simple answer, thats all. why google when im here with what i thought to be knowledgable people at the time. guess ill google touchy-feelly before asking anymore questions ..concerning anything

The consensus here seems to be a mold or bacteria causing DSS. I have not read anything conclusive as to what type of mold/bacteria it is or if it even is m/b or wether it is a single, specific m/b??? Could be different m/b in different parts of the country??? I do know that after 1 1/2 months it appears that I may have developed an allergic reaction to whatever it is. I say "may have" since I am not 100% about that either???
Apparently, at least in my case, defrost cycle is creating ideal temperature and moisture conditions in and around the evap coil for DSS to occur??? Using cooling mode does not seem to cause DSS even though similar conditions are present??? Usually with a unit operating in "emergency" mode (heat strips only) the compressor is not running, nothing is changing at the evap coil = no DSS??? In my case, powering the heat strips with the compressor running (defrost cycle only), seemed to reduce the stink considerably, possibly killing or burning off whatever as it passed the strips???
Exposing the evap coils to UVC light has worked for me so far. Others report it has not worked for them??? From what I have read, the coil must be exposed to sufficient UVC intensity and/or dwell for UVC to be effective.
Anyway, that is most of what I don't know about DSS... LOL!

Originally Posted by jatibb

new here, been following this. we have a new unit, replaced july 08. ac all summer good, after first few weeks of cold, dss. not always, not when emergency heat used, but 1- 2 times a day. am going to clean coils,pan,drain,filter... big question is ,what is this mold and is it harmfull? name with niger in it makes me think black mold?

THANKS, still looking into a uv light. on another note though, are the materials inside of a air handler built or capable of withstanding uv light all the time w/o breaking down? the sun can have pretty disasterous effects on some plastics,rubber parts etc..

That is a concern I have w/uv light also. From what I have read, almost all plastics will deteriorate to some degree when exposed to UV light, some faster and more severe than others. For the most part the only plastic I have in the coil cabinet is the drain pan liner. I intend to monitor that as I replace UVC lamps. At any rate I figured it was worth the risk + UVC has several other benefits in this application.
I reasoned it out this way: My new house stunk pretty bad and I suspected I was reacting physically to whatever was causing the stink. I figured I didn't have much to loose by trying the UVC treatment at that point. Hopefully someone will come up with what exactly is going on with DSS. I will deal with it again at that time. For now I can at least enjoy in my new house. I have notified my installing contractor of the problem and intend to contact the manufacturer in the near future.

possible silly and/or dumb question, if this mold grows on the coils is there anyway to kill it? the chemical listed earlier, is it a cleaner or does it just mask the odor of said mold? would it be possible to use a propane torch to heat the coils or would that damage coils and?or mold grow back anyway?

Well my turn I quess and hope we can come up with something. I'll run down my equipment and chnages to it over last few years (not much).
Built my house in 1993 and had a Tempstar 9 SEER Gas Pack (?) installed and it ran good for 11 years with no odors or problems. When it broke the day before Christmas my problem ended up being a cracked heat exchanger. I opted for a new unit as a friend of mine was then working with an HVAC contractor and gave me what I felt was a good deal. Back to my old unit and as I mentioned it never gave me any problems up until that day. My only "CON" about the system was that when the fan came on you had to turn up the TV because it sounded like a jet engine starting up.
New unit installed around Christmas, 13 SEER Amana GAS Pack with a stainless steel heat exchanger with lifetime warranty. Things went well until spring comes and we switched to a/c for first time and whew what a smell (dirty socks, vomit, or whatever it is) which lasted about 6 hours before it cleared the house. A week or so with no problems and it turned called and on come the heat and here comes the stinch from h@##, back to air couple of days later and same thing for about 6 hours or so and nothing for the entire rest of the summer unti the first day to use the heat. Gag time again for about 6 hours or so and that is the way it has been for 3 years. Contractor has came out and cleaned coils a couple of time, but know good and they pretty much threw up there hands and said it wasn't there unit causing it. My reply was, The problem did not start till you put your product in and the problem is still there because you put your product in. So fix it or take it out and I' found another one. Waiting to hear back from them but they don't have a clue.
My biggest question is - Why does it do it with new unit and not the old unit? Stainless steel heat exchanger? Slower (or quiter fan)? Air at register seems to be a little hotter with new unit as with older unit? Any thoughts!!!???? Thanks ahead of time
P.S. There was know ductwork done when the units were changed out.

uv or anit bacterial coating

A uv light light or a good anti bacterial coating on your heat exchanger should do the trick. Otherwise you might need to have your ducts cleaned. That could be part of the problem. the mold could be living in your ducts and when you turn switch your unit the mold molecules get agitated and blown around again. But I would try the uv lights or the coating first as that is most likely the problem